Dennis B. Herd - Texas Agricultural Extension Service / College Station
Where pasture is still plentiful, but low in quality, the following suggestions are made
concerning supplementation:
1. Provide a good mineral supplement which will maintain forage intake and efficient
utilization. A complete mineral supplement containing 10 to 20% salt, 12% calcium, 12%
phosphorus, 5% magnesium, 0.9% zinc, and 0.2% copper has worked well in many areas.
2. Feed one pound to two pounds per day of a high protein supplement to dry cows and
possibly as much as two pound to three pounds to lactating cows to maintain forage intake
and efficient utilization of the forage as well as the energy coming off the cow's back as
weight loss.
Oil meal supplements such as cottonseed meal, protein blocks, and liquid supplements
would be appropriate. The supplements are generally listed in order of their cattle
performance effectiveness and reverse order of convenience.
3. If only dry, dormant forage is available for more than 100 to 200 days, consider
supplementing or injecting vitamin A.
Where pasture is lacking in amount as well as quality, the following suggestions are offered:
1. If only slightly limited, the feeding of range cubes (20% protein) or mixtures of grain and
cottonseed meal at rates of 3 to 5 pounds per cow daily may work for a while. Cubes with
a large amount of natural protein and a low crude fiber level (less than 10%) would be
preferred.
2. When pasture becomes extremely short, purchase of hay or a replacement feed for the
pasture must be considered as well as selling of stock. Remember that most grass hay has
only 50 to 65% the energy content of grain so that one pound of grain can replace 1.5 to
2.0 pounds of hay. A pound of grain will only replace 1.2 to 1.4 pounds of alfalfa hay. It
doesn't make sense to pay $105 per ton for poor quality grass hay when grain would cost
very little more. It is necessary to start cows on grain slowly and feed so that all cows have
opportunity for their share of the feed. It is possible to feed up to 80% grain in a
maintenance diet for British bred cows, but such high levels should not be considered for
Brahman cattle. All cattle need some forage in the diet to minimize digestive problems.
In the absence of sufficient nutrients, particularly energy, cows lose considerable weight. When such
weight losses occur, milk production decreases and reproductive activity may cease. The end result
is light-weight calves and unbred cows. To prevent such undesirable effects, cows either must be
provided sufficient nutrients to avoid weight losses and maintain production requirements or they
must be relieved totally or partially from body stresses.
Unavailability of feeds or their unusually high cost often prohibits feeding lactating cows the
nutrients necessary for lactation and rebreeding. Production requirements of the mature cow for
which nutrients are needed include body maintenance, lactation and rebreeding. First-calf heifers and
young cows must have additional nutrients for growth. To reduce stress and lessen the total feed
necessary, the only production requirement that can be removed is lactation. Lactation stress may
be removed from cows or heifers by weaning calves after 60 to 80 days of age, or partially removed
by creep feeding and holding the calf off the cow for part of the day. In so doing, nutrient
requirements are lessened and reproductive activity is more likely to commence or be maintained.
Where considering early weaning, rations such as the one in Table 1 are used to start baby dairy
calves on feed and would work equally well for young beef calves. Such rations are commercially
available. A high quality hay should be fed with this mixture. As calves pass 4 to 6 months of age,
traditional feedlot rations containing 12 to 14% protein and 10 to 40% roughage may be self fed
depending on the level of performance desired.
Where hay is scarce, give ammoniated wheat straw a try. Ammoniation of straw with 60
pounds of anhydrous ammonia per ton of straw will increase cattle performance and make it possible
to utilize wheat straw as the only roughage in the diet, something not recommended for untreated
straw.
A summary of four trials is presented in Table 2 indicating that actual daily gain was improved
by ammoniation by .31 to .82 pounds daily. The improvement results because of increases in
digestibility and intake, intake improving by 20 to even 30%. As indicated, 2 to 3 pounds of
supplement or alfalfa hay were fed along with free choice wheat straw. Ammoniation does not make
wheat straw a complete feed. A good mineral supplement will be essential and supplementation with
1-2 pounds of natural preformed protein is advisable along with the non-protein nitrogen added by
ammoniation. Toxicity problems, involving calf losses and wild irrational cattle behavior, have been
reported when ammoniating high quality forages such as sorghum sudan hybrids. The problem
appears to be related to high available carbohydrate content and the reaction with ammonia to form
toxic methylimidazoles. Imidazole formation and toxicity problems have not been observed with
ammoniation of wheat straw or similar products. If you're short of forage and wheat straw is
available, give ammoniation a try.
Stay alert for potential problems which might result because of drought conditions:
1. Use of salt to limit feed intake may increase water intake 50 to 75% or approximately 50
gallons of additional water for each pound of salt. Water must not be limited in any way
or salt toxicity may result.
2. Over-consumption of urea-containing supplements by cattle on forage scarce ranges can
result in urea toxicity. Generally, cattle performance on urea-type supplements is also poor
whenever energy or forage is in short supply.
3. Hay cut under moisture stress conditions, especially sorghum type hays, may contain high
levels of nitrate. If in doubt, it would be good to test for nitrate before feeding such hays,
especially before feeding large amounts. Producers who cut drought corn or sorghum for
hay are enouraged to check nitrate levels before feeding. Be sure to take a good
representative sample when sending to the laboratory for analysis.
4. Prussic acid or cyanide poisoning can also be a problem in grazing drought stunted plants
such as Johnson grass, sorghum, sorghum hybrids, and sudan grass. If forage for hay is
allowed to sun cure thoroughly for three to five days, bleaching out any bright green color,
prussic acid should not be a problem.
5. Cattle grazing short pasture are more likely to consume toxic plants. See section in
rangeland management on toxic plants.
6. Alternate day feeding of protein supplements, like cottonseed cubes, has been recommended
to save labor. The practice is still good for high protein supplements but is not to be used
for grain type supplements. High energy supplements (grain, breeder cubes, etc.) should
be fed daily especially where three to six pounds or more daily may be fed. High energy
acid-producing feeds tend to decrease rumen pH and fiber digestion and alternate day
feeding of large amounts, more than four pounds, simply magnifies the decrease in rumen
pH. Further, unadapted cows should be started on grain feeding slowly or the problems of
acidosis, founder and even death may result.
7. Rumen impaction may result where cattle receive inadequate protein (less than 7 to 8% CP
in total diet) and too much of a low quality high fiber forage such as drought pasture or
prickly pear or forage substitutes such as peanut hulls, straws or gin trash. Lack of
adequate water will aggravate the impaction program.
8. Hardware disease. Hay harvested from vacant city lots, roadsides etc., broiler litter and
other such feed may contain nails, wire, or foreign objects which can pierce the rumen wall
resulting in death of the animal. Close observation of feeds and the use of magnets in
grinder/mixers can help to reduce the potential consumption of problem materials by
animals.
Chopping and Grinding Forages and Straw
When ruminant livestock cannot consume enough dry hay or roughage to meet nutritional
requirements, intake can be increased by chopping or grinding. This may be particularly important
when there is an abundant supply of roughage and grain is scarce or high priced. When roughage
supply is limited it may also be necessary to ensure complete consumption of coarse stems, moldy
portions, etc. Grinding prevents selective consumption and helps to mix and thus dilute portions of
the ration which by themselves are unpalatable or possibly toxic. Grinding does not in itself make the
feed any more nutritious; in fact it reduces the digestibility of the feed slightly, but because animals
can consume more, a larger proportion of the feed intake is available for production (growth), and
a smaller proportion is used for maintenance. Grinding also increases the ratio of propionic acid:
acetic acid in the rumen which improves feed efficiency in beef cattle but reduces butterfat content
of milk.
Guidelines
Don’t grind forage for any class of ruminant livestock when the animal is capable of consuming
amounts adequate to meet nutritional requirements. Grinding palatable rations for beef cows results
in either overfeeding (wastage of feed) or the need to limit feeding (labor is wasted and cows have
unsatisfied appetites).
Grind through one-half inch screen. Courser grinding may be all right for good-quality hay
when self-fed “basis”. However, coarser ground material will allow other ration ingredients to settle
out during handling and in self feeders, and may lead to bridging in the mixer and self feeder. Finer
grinding may be better for very low quality roughage but costs are too high.
Efficient grinding requires a high capacity grinder and a tractor large enough (100 HP or more)
to handle it. Power requirements increase considerably as the moisture content of the hay increases.
That is why it is important to put hay and straw up in a dry condition (less than 20% moisture) and
to protect it from taking on moisture. Also grinding damp hay leads to bridging and may promote
heating in large self feeders it left too long before feeding. When complete rations are to be
processed, use a grinder mixer. If forage is to be self-fed and supplementary feed hand fed, a tub
grinder may be used. (If roughage is in the form of round bales, a tub grinder will have to be used).
When using high levels of poor-quality roughage in the diet, proper supplementation is essential
to avoid impaction.
Since many livestock procedures will be using unfamiliar feeds or rations during periods of feed
shortage, they should keep a close watch over animal performance and adjust rations as necessary
to meet production requirements.
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